Background and Aim: Patellofemoral pain syndrome is one of the most common knee disorders in the athletes and women. Despite use of water-based exercise in the treatment of musculoskeletal disorders and sport injuries, its impact on the pain and knee function in the patients with patellofemoral pain syndrome has not been investigated appreciably. The present study made a comparison between the effects of water-based exercise and conventional land- based exercise in the female athletes with patellofemoral pain syndrome.

Material and Methods: 20 collegiate athletes with patellofemoral pain syndrome were included in this study and randomly assigned to two groups: water-based (n = 10) and Land-based (n = 10) groups.

Land – based protocol was performed in the gym and water-based training was implemented in the pool. Exercises were designed to strengthen the hip abductors and external rotator muscles. We used NRS to assess pain intensity, and Kujala and LEFS scale for the assessment of the knee function in various activities before and after the exercises protocols. We used repeated measures ANOVA for analysis of the effects of the therapeutic interventions.

Results: According to the results of repeated measure ANOVA we found significant differences in NRS (p=0.040) and LEFS (p=0.024) after intervention between the two groups. Statistical analysis showed no significant difference in kujala scores between the two groups (p=0.927).

Conclusion: The results showed that water-based exercise as a therapeutic modality was more effective in reducing the pain and improvement of the knee function in the patients with patellofemoral pain syndrome, compared to land-based exercise.